The present invention relates to a new and improved method and apparatus for securing a suture against movement relative to body tissue by using a retainer to grip the suture.
Difficulty has been encountered in securing sutures against movement relative to body tissue. A knot may be tied in a suture to prevent loosening of the suture. However, the knot weakens a portion of the suture and reduces the overall force transmitting capability of the suture. In addition, a suture which is held by a knot applies force to a relatively small area of the body tissue and tends to cut or separate the body tissue. Many operations are conducted in very restricted space where the tying of a knot is difficult.
Various methods of securing a suture against movement relative to body tissue are disclosed in U.S. Pat. Nos. 3,513,848; 4,662,068; 4,935,028; 5,306,280; and 5,593,425. Although these and other known methods of securing a suture have, to a greater or lesser extent, been successful, it is desirable to simplify the securing of a suture against movement relative to body tissue. It is also desirable to be certain that the suture applies a desired amount of force to the body tissue when the suture is secured. The overall force transmitting capability of the suture should be maximized without concentrating the force at a small area on the body tissue.
The present invention provides a new improved method and apparatus for use of securing a suture relative to body tissue. A portion of the suture is enclosed with a first member. Although the first member may have many different configurations, in one embodiment of the invention, the first member has a tubular configuration. The first member is moved along the suture toward the body tissue with the suture extending through a passage in the first member. The first member is then deformed to change the configuration of the first member. The first member may be deformed by bending the first member to grip the suture which extends through the passage in the first member. The first member is retained in the bent configuration by a holder.
The holder may have many different constructions that may include either one part or a plurality of parts. In specific embodiments of the holder, the holder forms a recess. The first member is at least partially located in the recess in the holder. The holder applies force against the first member to maintain the first member in its second or bent configuration.
In one specific embodiment of the invention, the holder is formed as one piece. In another embodiment of the invention, the holder is formed by a plurality of pieces which are interconnected. The holder may be formed with a generally C-shaped configuration to form a recess in which the first member is inserted. Alternatively, the holder may be formed of a plurality of parts which are interconnected with the first member between the parts of the holder.
It is contemplated that, if desired, the suture retainer could include a first member which is deflected and subsequently released to grip a portion of the suture between the first member and a second member. The suture may be wound for one or more turns around the first member before the first member is released. The first member may be released in a recess formed in the second member to press the suture against the second member with the first member. Alternatively, the second member could be received in a recess in the first member and the suture pressed against the second member by the first member.
In still other embodiments of the invention, the retainer includes the first and second members which are movable relative to each other to grip the suture between the members. The members may have a tapered configuration and/or a thread convolution which grips the suture. Alternatively, the retainer could be formed with a plurality of fingers which extend into a plurality of recesses to grip the suture. A pair of cam members may be utilized to apply force against the suture to hold the suture.
A tissue fixation system constructed in accordance with one of the features of the present invention is used to connect thick and thin layers of tissue. The tissue fixation system is located equal distances from the ends of the thick and thin layers of tissue.
In should be understood that a suture retainer constructed in accordance with the present invention may have many different configurations. It should also be understood that a suture retainer constructed in accordance with the present invention could hold a suture in many ways. The invention should not, except as required by the claims, be limited to any specific construction of the retainer and/or manner of holding the suture.